Patent Document 1 describes a communication terminal device which can use plural communication channels between itself and another communication terminal and which performs communication using communication identifiers for specifying communication channels. When a terminal application is activated, the communication terminal device communicates with the counterpart communication terminal using plural communication identifiers to collect information, such as response times and loss rates, representing communication quality of plural communication channels and determines, based on the collected information, a communication channel to be used.
Patent Document 1: Japanese Patent Laid-Open No. 2006-324945